Should this be "area density" instead of "solid angle density" in the book?

[Enigmatisms]

In PBR-book chapter 16.3, when the book is introducing the function PdfLightOrigin, it says:

<<Return solid angle density for non-infinite light sources>>

The returned value is directly assigned to some_vertex.pdfFwd. Since pdfFwd field in the vertex should store density defined in area measure for MIS uses. Some implementation of Pdf_Le (which returns pdf_pos and is directly used in PdfLightOrigin) also indicate this, for example, diffusive area source returns pdf_pos = 1 / Area().
Upon first reading this, I directly implemented PdfLightOrigin to return solid angle density for all light sources, but latter I think it doesn't make any sense... Could this be a mistake? Like, it were copy-pasted from the introduction of infinite light source procedure above?